Various devices have been developed theretofore for supporting screen or storm window sash on a step ladder for convenience in painting, puttying, glazing and the like. U.S. Pat. No. 2,015,378 discloses a screen ladder jack in the form of an elongated bar adapted to be mounted on the step of a ladder and having a T-shaped forward-end portion for supporting the lower end of a sash. U.S. Pat. No. 2,451,020 discloses a bracket formed of twisted wire having a pair of wire hooks at one end for engaging both the step of a step ladder and its side rail-- and an upstanding wire loop at its forward end for holding the bottom edge of a sash; and U.S. Pat. No. 2,398,617 discloses ladder attachments in the form of brackets pivotally secured at their inner ends to the rails of the ladder and formed with serrated edges at their forward ends for supporting the bottom edge of a screen or storm sash.